Sorry to hear about your Google Hub Max, but thanks for bringing this up. I know how hard it is to not have a working device when needed - I'd love to help.
To confirm, do you have other Nest Hub Max so we can check if the issue is with the power adapter or the device itself. Could you tell us also when you purchased the device?
Looking forward too your response.
I am having the same problem. Google Support tells me the problem is with the hardware. I do not think so. The problem came up after the latest upgrade. I cannot Factory Reset the Hub Max at all. It is totally ludicrous to see a hardware device fail just after two years. I spent over $200 to get acquire it. Hub Max has poor engineering. Instead of doing a Factory Reset by using a pin hole with a needle, the device is designed to do a software factory reset.
I am a technology person and I understand tech engineering very well. I would never ever recommend any of Google Nest devices to anyone. I have Apple devices running for over fifteen years even with an outdated iOS version.